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DOI | 10.1126/science.abh3418 |
Role of the ionic environment in enhancing the activity of reacting molecules in zeolite pores | |
Niklas Pfriem; Peter H. Hintermeier; Sebastian Eckstein; Sungmin Kim; Qiang Liu; Hui Shi; Lara Milakovic; Yuanshuai Liu; Gary L. Haller; Eszter Baráth; Yue Liu; Johannes A. Lercher | |
2021-05-28 | |
发表期刊 | Science
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出版年 | 2021 |
英文摘要 | Brønsted acidity is introduced into microporous zeolites through the addition of framework aluminum. Pfriem et al. show that in the presence of water, the limited volume in the microchannels of zeolite H-MFI leads to a high concentration of hydrated hydronium ions at aluminum sites. The resulting high charge density creates a highly non-ideal solvation environment and, for cyclohexanol dehydrogenation, the charged carbenium-ion transition state was stabilized. A higher rate was maintained with lower-acidity sodium ion–exchanged zeolites that had the same high ionic strength. Science , abh3418, this issue p. [952][1] Tailoring the molecular environment around catalytically active sites allows for the enhancement of catalytic reactivity through a hitherto unexplored pathway. In zeolites, the presence of water creates an ionic environment via the formation of hydrated hydronium ions and the negatively charged framework aluminum tetrahedra. The high density of cation-anion pairs determined by the aluminum concentration of a zeolite induces a high local ionic strength that increases the excess chemical potential of sorbed and uncharged organic reactants. Charged transition states (carbocations for example) are stabilized, which reduces the energy barrier and leads to higher reaction rates. Using the intramolecular dehydration of cyclohexanol on H-MFI zeolites in water, we quantitatively show an enhancement of the reaction rate by the presence of high ionic strength as well as show potential limitations of this strategy. [1]: /lookup/doi/10.1126/science.abh3418 |
领域 | 气候变化 ; 资源环境 |
URL | 查看原文 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/328864 |
专题 | 气候变化 资源环境科学 |
推荐引用方式 GB/T 7714 | Niklas Pfriem,Peter H. Hintermeier,Sebastian Eckstein,et al. Role of the ionic environment in enhancing the activity of reacting molecules in zeolite pores[J]. Science,2021. |
APA | Niklas Pfriem.,Peter H. Hintermeier.,Sebastian Eckstein.,Sungmin Kim.,Qiang Liu.,...&Johannes A. Lercher.(2021).Role of the ionic environment in enhancing the activity of reacting molecules in zeolite pores.Science. |
MLA | Niklas Pfriem,et al."Role of the ionic environment in enhancing the activity of reacting molecules in zeolite pores".Science (2021). |
条目包含的文件 | 条目无相关文件。 |
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